Here is an example of using Plack to capture form queries:

use Data::Dumper;
use Plack::Request;
use Plack::Response;

my $app = sub {
    my $req = Plack::Request->new(shift);
    my $query = $req->parameters;
    my $res = Plack::Response->new(200);
    $res->body('<pre>' . Dumper($query) . '</pre>');
    $res->finalize;
};
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